Smiths Aerospace
Electronic Systems – Malvern
DOC NO.0134ED
MAINTENANCE MANUAL SUPPLEMENT
BOEING B737-100/200/300/400/500
28-41-04
Remove master indicator.
(AMM 28-41-04/401)
Disconnect A/C Harness from TSU.
Repair fault in A/C harness
(WDM 28-41-01)
>50 megohm
<50 megohm
Measure resistance from Tank Lo-Z to
Hi-Z at the indicator connector.
(AMM 28-41-04/501)
Remove bussing plug and measure
resistance across individual tank units
>50 megohm
<50 megohm
Measure resistance from Tank Lo-Z to
Hi-Z at tank wall
Clear FQI errors and
confirm error persists
Remove TSU harness from
tank wall bussing connector
Replace TSU
(AMM 28-41-04/401)
Repair/Replace applicable tank
unit/harness
(AMM 28-41-81/401)
>50 megohm
<50 megohm
Repair/Replace Harness
(AMM 28-41-44/401)
Operational Test
(AMM 28-41-04/501)
Err 5: Tank Lo-Z Line Short to Hi-Z
Figure 106
Page 119
April 19/02
Airplanes with Smiths 2307 Model Fuel Quantity
Indicators with TSU
EFFECTIVITY